A newly unearthed essay, “Are We Alone in the Universe,” by Winston Churchill reveals he was open to the possibility of life on other planets. In 1939, a year following the radio broadcast of Ortson Welles’ War of the Worlds with World War 11 breaking out, Churchill discussed the concept of habitable zones more than 50 years before the discovery of exoplanets. Churchill’s thinking mirrors many modern arguments in astrobiology and builds on the Copernican Principle – the idea that human life on Earth shouldn’t be unique given the vastness of the Universe.

The 11-page typed draft, “Are We Alone in the Universe,” probably intended for a newspaper, was updated in the 1950s but never published. n the 1980s, the essay was passed to a US museum, where it sat until its rediscovery last year. According to BBC News, the document was uncovered in the National Churchill Museum in Fulton, Missouri, by the institution’s new director Timothy Riley. Mr Riley then passed it to the Israeli astrophysicist and author Mario Livio who describes the contents in the latest issue of Nature journal.

Churchill’s interest in science is well-known: he was the first British prime minister to employ a science adviser, Frederick Lindemann, and met regularly with scientists such as Sir Bernard Lovell, a pioneer of radio astronomy. Documented engagement with the scientific community was partly related to the war effort, but he is credited with funding UK laboratories, telescopes and technology development that spawned post-war discoveries in fields from molecular genetics to X-ray crystallography.

Churchill defined life as the ability to “breed and multiply” and noted the vital importance of liquid water, explaining: “all living things of the type we know require [it].” More than 50 years before the discovery of exoplanets, he considered the likelihood that other stars would host planets, concluding that a large fraction of these distant worlds “will be the right size to keep on their surface water and possibly an atmosphere of some sort”. He also surmised that some would be “at the proper distance from their parent sun to maintain a suitable temperature”.

Churchill also outlined what scientists now describe as the “habitable” or “Goldilocks” zone – the narrow region around a star where it is neither too hot nor too cold for life. The essay predicts great opportunities for exploration of the Solar System. “One day, possibly even in the not very distant future, it may be possible to travel to the Moon, or even to Venus and Mars,” Churchill wrote.

But the politician concluded that Venus and Earth were the only places in the Solar System capable of hosting life, whereas we now know that icy moons around Jupiter and Saturn are promising targets in the search for extra-terrestrial biology. However, such observations are forgivable given scientific knowledge at the time of writing.

With the gathering storm clouds over Europe, Churchill wrote: “I for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures, or that we are the highest type of mental and physical development which has ever appeared in the vast compass of space and time.”

Livio told BBC News that there were no firm plans to publish the article because of issues surrounding the copyright. However, he said the Churchill Museum was working to resolve these so that the historically important essay can eventually see the light of day.

The artist’s conception at the top of the page, depicts an Earth-like planet orbiting an evolved star that has formed a stunning planetary nebula. (David A. Aguilar Harvard=Smithsonian CfA)